With the ever increasing prevalence of wireless communication technology in aspects of the modern world, there has been a growing trend in recent years toward the implementation of wireless control (for example radio frequency control) within lighting systems. Wireless control of lighting affords users greater ease and flexibility in the operating of lamps and luminaires, rendering not only the standard operating processes of, for e.g., activating, deactivating, dimming etc, more convenient, but also opening the way for an entire new range of added control functionalities, such as internet-based remote control, timers and routines to control lights, sensor-activated lighting, and implementation of time or activity-based lighting ‘moods’.
To incorporate wireless control within a lighting device, it is necessary to build in wireless transceiver components (for example an antenna element) to the body of the device. There are two main options for the installation of the antenna element within a luminaire or lamp. In a first option, the antenna element is housed within a dedicated metal enclosure, located in the main body of the device. In this case however, the wireless (e.g. RF) signal is partially blocked by the metal of the casing, and consequently the sensitivity and transmission range of the device is limited.
To improve the RF signal, the antenna element may alternatively be positioned within the optical (light output) portion of the lighting device, allowing less attenuated signal communication to and from the antenna. Inclusion of the antenna within optical parts however, incurs a consequent impairment of the optical performance of the device. In particular, for wireless controlled lighting devices which incorporate colour-tuning functionality, an antenna element in the optical chamber of the lamp can interfere with the colour mixing operation, with a resultant impact on the quality of the colour output. In addition, the antenna element may cast a noticeable shadow within the output light distribution.
There is therefore a need for a lighting device having wireless control functionality, but with a wireless antenna element which is neither signally attenuated by enclosure within a metal casing, nor situated such that it interferes with the optical output of the device.
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